1. Field of the Invention
This invention concerns internal combustion engines and more particularly two cycle internal combustion piston engines.
2. Description of the Prior Art
Two cycle piston engines typically rely on cylinder wall porting to allow a fresh charge to be taken in and exhaust products to be exhausted. While simple, this allows intermixing of the fresh charge and a residual portion of the exhaust products from the previous firing cycle. Further, excessive amounts of unburned fuel passes out with the exhaust causing a high level of pollutants to be discharged into the atmosphere and reducing engine efficiency.
More sophisticated valving alleviates the problem, but this adds the cost of a cam shaft and valve operating components.
It is the object of the present invention to provide an arrangement for controlling intake and exhaust from the cylinder of a two cycle piston engine which minimizes exhaust pollution and maximizes engine efficiency while not requiring a complex valve operating mechanism.